was no hybrid decimal/sexagesimal calculation in China. Part II dealt with operation of subtraction, multiplication, division, extraction of square root and cubic root in sexagesimal number system. There was only positional decimal arithmetic in China, never any sexagesimal arithmetic. Unlike Abu'l-Hasan al-Uqlidisi's Kitab al-Fusul fi al-Hisab al-Hindi (The Arithmetics of Al-Uqlidisi) where the basic mathematical operation of addition, subtraction, multiplication and division were described in words, ibn Labban's book provided actual calculation procedures expressed in Hindu-Arabic numerals. Decimal arithmetics Addition Kushyar ibn Labban described in detail the addition of two numbers. The Hindu addition is identical to rod numeral addition in Sunzi Suanjing There was a minor difference in the treatment of second row, in Hindu reckoning, the second row digits drawn on sand board remained in place from beginning to end, while in rod calculus, rods from lower rows were physically removed and add to upper row, digit by digit. Subtraction In the 3rd section of his book, Kushyar ibn Labban provided step by step algorithm for subtraction of 839 from 5625. Second row digits remained in place at all time. In rod calculus, digit from second row was removed digit by digit in calculation, leaving only the result in one row. Multiplication Kushyar ibn Labban multiplication is a variation of Sunzi multiplication. Division Professor Lam Lay Yong discovered that the Hindu division method describe by Kushyar ibn Labban is totally identical to rod calculus division in the 5th-century Sunzi Suanjing. Besides the totally identical format, procedure and remainder fraction, one telltale sign which discloses the origin of this division algorithm is in the missing 0 after 243, which in true Hindu numeral should be written as 2430, not 243blank; blank space is a feature of rod numerals (and abacus). Divide by 2 Divide by 2 or "halving" in Hindu reckoning was treated with a hybrid of decimal and sexagesimal numerals: It was calculated not from left to right as decimal arithmetics, but from right to left: After halving the first digit 5 to get 2, replace the 5 with 2, and write 30 under it: 5622 30 Final result: 2812 30 Extraction of square root Kushyar ibn Labban described the algorithm for extraction of square root with example of Kushyar ibn Labban square root extraction algorithm is basically the same as Sunzi algorithm The approximation of non perfect square root using Sunzi algorithm yields result slightly higher than